Noninvasive photoacoustic measurement of the composite indicator dilution curve for cardiac output estimation

Recently, the measurement of indicator dilution curves using a photoacoustic (PA) technology was reported, which showed promising results on the noninvasive estimation of cardiac output (CO) that is an important hemodynamic parameter useful in various clinical situations. However, in clinical practice, measuring PA indicator dilution curves from an arterial blood vessel requires an ultrasound transducer array capable of focusing on the targeted artery. This causes several challenges on the clinical translation of the PA indicator dilution method, such as high sensor cost and complexity. In this paper, we theoretically derived that a composite PA indicator dilution curve simultaneously measured from both arterial and venous blood vessels can be used to estimate CO correctly. The ex-vivo and in-vivo experimental results with a flat ultrasound transducer verified the developed theory. We believe this new concept would overcome the main challenges on the clinical translation of the noninvasive PA indicator dilution technology.OCIS codes: (170.0170) Medical optics and biotechnology, (170.3890) Medical optics instrumentation, (170.5120) Photoacoustic imaging, (170.4580) Optical diagnostics for medicine, (170.3880) Medical and biological imaging     

In vivo multiplexed molecular imaging of esophageal cancer via spectral endoscopy of topically applied SERS nanoparticles

The biological investigation and detection of esophageal cancers could be facilitated with an endoscopic technology to screen for the molecular changes that precede and accompany the onset of cancer. Surface-enhanced Raman scattering (SERS) nanoparticles (NPs) have the potential to improve cancer detection and investigation through the sensitive and multiplexed detection of cell-surface biomarkers. Here, we demonstrate that the topical application and endoscopic imaging of a multiplexed cocktail of receptor-targeted SERS NPs enables the rapid detection of tumors in an orthotopic rat model of esophageal cancer. Antibody-conjugated SERS NPs were topically applied on the lumenal surface of the rat esophagus to target EGFR and HER2, and a miniature spectral endoscope featuring rotational scanning and axial pull-back was employed to comprehensively image the NPs bound on the lumen of the esophagus. Ratiometric analyses of specific vs. nonspecific binding enabled the visualization of tumor locations and the quantification of biomarker expression in agreement with immunohistochemistry and flow cytometry validation data.OCIS codes: (170.5660) Raman spectroscopy, (170.2150) Endoscopic imaging, (110.2350) Fiber optics imaging, (170.0170) Medical optics and biotechnology, (170.2680) Gastrointestinal, (160.4236) Nanomaterials     

Is albuminuria an indicator of myocardial dysfunction in diabetic patients without overt heart disease? A study with Doppler strain and strain rate imaging

The aim of this study was to address whether albuminuria could predict myocardial dysfunction in diabetic patients without overt heart disease. We studied 67 patients with normal left ventricular (LV) ejection fraction and no evidence of LV hypertrophy or coronary artery disease (47 patients with type 2 diabetes mellitus and hypertension and 20 patients with hypertension only). Diabetes patients were divided into 3 groups based on albuminuria status: group II = no albuminuria (n = 20, <30 mg/d), group III = microalbuminuria (n = 13, 30-300 mg/d), and group IV = macroalbuminuria (n = 14, >300 mg/d). Twenty patients with hypertension only served as a control group (group I). Conventional 2-dimensional and Doppler echocardiography was done. Peak strain, peak systolic strain rate (SR), and peak diastolic SR of 6 LV segments in the apical views were measured and averaged in each patient. Conventional 2-dimensional parameters such as LV ejection fraction; left atrium volume index; LV mass; deceleration time; and mitral early peak, mitral late peak, myocardial early peak diastolic, and myocardial peak systolic velocities were not different among the 4 groups. However, peak strains were significantly lower in group III (P = .002) and group IV (P < .001) than in group I; and the absolute value of peak systolic SR was lower in group III (P = .033) and group IV (P < .001) than in group I. Furthermore, the value of peak diastolic SR was lower in group IV than in group I (P = .014). In diabetic patients with albuminuria, Doppler strain and SR imaging detected subclinical LV systolic and diastolic dysfunction; and albuminuria was associated with myocardial dysfunction in diabetic patients without overt heart disease.     

亚低温在蛛网膜下腔出血急性期的脑保护作用

亚低温对脑动脉瘤性蛛网膜下腔出血急性期脑损伤保护作用的研究报道较少。在动脉瘤性蛛网膜下腔出血急性期,有多种脑损伤机制参与脑损伤的发生。亚低温在脑梗死早期能对抗多种脑损害因素,应用于动脉瘤性蛛网膜下腔出血急性期,有可能发挥脑保护作用。     

Alteration in the Sensitivity of GABAA Receptors to Allosteric Modulatory Drugs in Rat Hippocampus After Chronic Intermittent Ethanol Treatment

Chronic intermittentethanol (CIE)-treated rats exhibited a kindlinglike persistent increase in withdrawal hyperexcitability. The alteration of GABA_A receptor (QABA_AR) function in the hippocampus was suggested as a possible mechanism underlying the hyperexcitability observed in CIE rats, because (1) GABA_AR agonist (muscimol)-evoked ³⁸Cl- efflux was decreased; (2) paired-pulse inhibition in the CA1 area, predominantly due to GABA_AR-mediated recurrent inhibition, was persistently decreased; and (3) GABA_AR subunit expression was altered in the hippocampus from CIE rats. To further characterize the functional alteration of GABA_AR after CIE treatment, their sensitivity to acute ethanol, a steroid anesthetic (alphaxalone), and a benzodiazepine inverse agonist (DMCM; methyl-6, 7-dimethoxy-4-ethyl-β-carboline-3-carboxylate) were studied using either synaptically evoked GABA_AR responses or exogenously applied muscimol-evoked responses in hippocampal slices. Bath application of ethanol (60 mM) enhanced the area of GABA_AR-mediated inhibitory postsynaptic potentials in the hippocampal CA1 region from control and CIE rats, and this potentiation was significantly (p = 0.027) greater in CIE rats (98%) than in control rats (53%). The positive modulatory effect of alphaxalone (1 μM) on GABAAR-inhibitory postsynaptic potentials was not significantly different between control and CIE rats (p = 0.375), whereas alphaxalone allosterically increased [³H]flunitrazepam binding in the CA1 area only in CIE rats (by 20 to 25%, p < 0.01), but not in controls. On the other hand, the negative modulatory effect of DMCM (1 μM) on muscimol-evoked responses was significantly larger in CIE rats (p = 0.002). These results suggest that the sensitization of GABA_AR to acute ethanol and benzodiazepine inverse agonists, and possibly neurosteroids, may underlie ethanol dependence after multiple ethanol withdrawal episodes. These altered pharmacological properties are most consistent with changes in the subunit composition in the CA1 area of this rat model of alcohol dependence.     

Comparison of skin sensory thresholds using pre-programmed or single-frequency transcutaneous electrical nerve stimulation

[Purpose] The purpose of the present study was to compare the sensory thresholds of healthy subjects using pre-programmed or single-frequency transcutaneous electrical nerve stimulation. [Subjects] Ninety healthy adult subjects were randomly assigned to pre-programmed or single-frequency stimulation groups, each consisting of 45 participants. [Methods] Sensory thresholds were measured in the participants’ forearms using von Frey filaments before and after pre-programmed or single-frequency transcutaneous electrical nerve stimulation, and the result in values were analyzed. [Results] Significant increases in sensory threshold after stimulation were observed in both groups. However, there were no significant differences between the two groups in sensory thresholds after stimulation or in the magnitude of threshold increases following stimulation. [Conclusion] Our results show that there are no differences between sensory threshold increases induced by pre-programmed and single-frequency transcutaneous electrical nerve stimulation.Key words: Pre-programmed TENS, Sensory threshold, Single-frequency TENS     

ISPD Cardiovascular and Metabolic Guidelines in Adult Peritoneal Dialysis Patients Part I – Assessment and Management of Various Cardiovascular Risk Factors

Cardiovascular disease contributes significantly to the adverse clinical outcomes of peritoneal dialysis (PD) patients. Numerous cardiovascular risk factors play important roles in the development of various cardiovascular complications. Of these, loss of residual renal function is regarded as one of the key cardiovascular risk factors and is associated with an increased mortality and cardiovascular death. It is also recognized that PD solutions may incur significant adverse metabolic effects in PD patients. The International Society for Peritoneal Dialysis (ISPD) commissioned a global workgroup in 2012 to formulate a series of recommendations regarding lifestyle modification, assessment and management of various cardiovascular risk factors, as well as management of the various cardiovascular complications including coronary artery disease, heart failure, arrhythmia (specifically atrial fibrillation), cerebrovascular disease, peripheral arterial disease and sudden cardiac death, to be published in 2 guideline documents. This publication forms the first part of the guideline documents and includes recommendations on assessment and management of various cardiovascular risk factors. The documents are intended to serve as a global clinical practice guideline for clinicians who look after PD patients. The ISPD workgroup also identifies areas where evidence is lacking and further research is needed.     

Immediate effects of an end-range mobilization technique on shoulder range of motion and skin temperature in individuals with posterior shoulder tightness

[Purpose] This study investigated the effects of an end-range mobilization technique on the range of motion of the glenohumeral internal rotation and the skin temperature of the shoulder in individuals with posterior shoulder tightness. [Subjects] Thirteen subjects with posterior shoulder tightness who had glenohumeral internal rotation deficit ≥ 15° participated. [Methods] All subjects underwent glenohumeral joint end-range mobilization intervention. The internal rotation range of motion of the glenohumeral joint was measured by a goniometer and the shoulder skin temperature was measured by a digital infrared thermographic imaging device before and immediately after the intervention. Paired t-tests were used to analyze the differences in these parameter pre and post-intervention. [Results] The glenohumeral internal rotation range of motion and skin temperature of the posterolateral shoulder in increased significantly post-intervention. [Conclusion] The end-range mobilization technique is effective for increasing the glenohumeral internal rotation range of motion and skin temperature of the shoulder in individuals with posterior shoulder tightness.Key words: End-range mobilization, Glenohumeral internal rotation deficit, Posterior shoulder tightness